This invention relates generally to exercise devices and more particularly to devices which provide a variable amount of resistance to the user during an exercise movement.
According to current concepts, muscle development is best achieved by exercises which are carried out in such a manner that the muscles are continuously worked at a level of nearly maximum effort during the exercise.
Most currently known exercise devices are not capable of providing this type of exercise because the resistance which they exert remains constant or decreases throughout the exercise movement while the strength exertable by the user's muscles varies at different points in the movement, and generally increases where the machine resistance decreases. Therefore, a degree of resistance which, at one point in an exercise movement may require near maximum effort to overcome, will at some other point in the movement be either too much or too little.
It has, therefore, been a desire of both exercisers and coaches to have an exercise device which can vary the applied resistance during an exercise movement to correspond with variations in available muscle strength. Attempts have been made to satisfy this desire, however, the resultant devices have been excessively complex and expensive.
It is, therefore, a major object of my invention to provide an exercise device in which the resistance varies as the user moves the device through the exercise cycle.
It is also an object of my invention to provide an exercise device of the type described in which the manner of variation of the resistance during the exercise cycle is adjustable.
It is another object of my invention to provide an exercise device of the type described in which the variation of resistance occurs because of changes in the length of a lever arm through which the resistance is applied.
It is a further object of my invention to provide an exercise device of the type described in which the resistance is varied by the vectoring of the force applied to the machine by the user during the exercise cycle.
Still another object of my invention is to provide an exercise device structured to readily withstand heavy forces and extensive use.
Still a further object of my invention is to provide an exercise device of the type described in which the resistance varying mechanism can be incorporated into many types of existing exercise devices without substantially increasing their cost.
Yet another object of my invention is to provide an exercise device of the type described which is relatively inexpensive to manufacture, simple to use and substantially maintenance free.